Differentiated integration (DI) is often portrayed as leaving political disagreements to one side and thereby allowing the integration process to proceed. This paper argues that instead, any institutional design for DI involves highly political choices about which actors and ideas should be represented in policy processes, how and based on which conditions, some of which are fairer to all concerned, others less so. We develop the argument in two main steps. In the first step, we explore how three established theories of European integration (liberal intergovernmentalism, neo-functionalism and demoicracy) can address the question of fairness in institutional design as regards DI. Whereas liberal intergovenmentalists prioritise the interests of states and neo-functionalists the interests of citizens, demoicrats try to balance the fair treatment of the two. In a second step, we will apply the three approaches to concrete questions of procedural and substantial fairness in institutional design as regards DI, thereby sketching the political options that can be derived from the three approaches. The discussion will reveal how some choices of institutional design will deepen power asymmetries and potentially create new divisions whilst others should avoid these pitfalls.
